This invention relates generally to air conditioner evaporator systems, and more particularly to an improved coolant inlet manifold for distribution of coolant into an evaporator coil.
In many refrigeration or air conditioning systems, the cooling or evaporator coil of such systems includes a plurality of coils connected together in parallel wherein the coolant or refrigerant is divided within a distribution head or manifold connected between the coils and an expansion device such as an expansion valve which receives compressed refrigerant for metered flow into the inlet manifold. These parallel evaporator tubes are useful in reducing resistance to refrigerant flow and increase the overall efficiency of the evaporator coil. Reduced resistance or friction to refrigerant flow is useful as it avoids build-up of pressure which causes the liquid refrigerant to boil at the resulting elevated temperature thereby reducing cooling efficiency of the evaporator coil.
Even though these evaporator coils having parallel flow tubes do indeed reduce resistance to refrigerant flow, nonetheless, because each tube does not receive refrigerant of the same homogeneous blend of liquid and gaseous from conventional inlet manifolds, at least a portion of the surface of the coil is less efficient.
Many efforts have been made to resolve this problem and to ensure that a more uniform and optimum homogeneous blend of gas and liquid refrigerant is continuously introduced into all parallel tubes within the evaporator coil. An early invention of J. Boyle is disclosed in U.S. Pat. No. 2,461,876 which is generally to a uniquely shaped housing wherein refrigerant flow is disbursed by a conical-tipped member which includes downstream apertures for introduction of the refrigerant into each of the evaporator coils.
A somewhat later device is disclosed in U.S. Pat. No. 4,543,802 to Ingelmann which is directed to the addition of a mixing means disposed between the inlet manifold or flow divider and the expansion valve. Another device or system intended to at least partially address this problem with respect to automotive air conditioners is disclosed in U.S. Pat. No. 4,593,539 to Humpolik, et al. which discloses a uniquely shaped manifold having an initial elongated quieting section through which the refrigerant flows after which the flow is reversed and distributed through a plurality of spiraling sections for distribution through each evaporator tube of the evaporator coil.
Applicant is also aware of the West German Pat. No. 382 233 B to Hercog which appears to disclose a counterflow arrangement of refrigerant through the refrigerant coils at the evaporator coils.
The present invention provides a simpler and improved inlet manifold which provides for the continuous mixing and blending of the refrigerant whereby an even, uniform distribution of the refrigerant is provided into each tube of the evaporator coil so that efficiency of the evaporator coil is increased.